Evaluation of carbon grid reinforcement in asphalt pavement

Abstract

• Carbon grid reinforcement mixtures exhibited a higher performance on fatigue cracking resistance. • Both grid reinforced mixtures met the minimum shear bonding strength requirement of 225 kPa. • The grid efficiency factor of the G17 mixture outperforms the G20 mixture, which was 2.5 compared to 1.16. • The performance year of grid mixtures was 2–4 times higher than the control mixture. • G17 and G20 alternatives reduced 43% and 13% total cost compared to C00 alternative through 20-year service. This study aims to analyze the advantages of carbon grid reinforcement in asphalt pavement based on performance tests, pavement design, and life cycle cost analysis (LCCA). The improvement in mechanical property was examined by overlay tester (OT), four-point bending, Hamburg wheel tracking, and shear bond strength test. Grid efficiency factor (GEF) was computed to evaluate the enhancement of cracking resistance. Based on the OT results, the performance year was quantified by a mechanical-empirical model of reflective cracking rate. Then, the outcomes from the performance year analysis were used to determine the economic effect through 20-year service by life cycle cost analysis (LCCA). Overall, carbon grid reinforcement not only enhances the performance of asphalt mixture but also prolongs service life, thus beneficial in cost-effectiveness. For instance, the resistance to reflection cracking was improved; deformation and rutting velocity was reduced due to the presence of a grid layer; GEFs of grid reinforced mixtures ranged from 1.5 to 2.5. Finally, the asphalt mixture containing grid would increase performance year by 2–4 times than that of conventional asphalt mixture. Therefore, the total cost of the grid reinforced alternative was reduced by approximately 43% through a 20-year service.